1892.] PROSSER THE GENESEE SECTION. 63 



DEPTH. "^NES^' KIND OF ROCK. 



135' Mostly olive and gray shale. - 



1255 

 1285' 



30' Light gray sandstone. 



Mainly brownish-gray sandstone. 

 { Stray sand at 1285'. 

 108' •< Top of gas sand at 1357'. 

 ( Bottom " " " T-.82'. 



1393 



1415' 



26' 



Greenish-gray shale. 



pjrownish-gray sandstone. 

 J Top of oil sand at 1415'. ) 

 I Bottom " " " 1441'. f 

 1441' Bottom of well. 



In December, 1887, Mr. Hatch sent me three specimens of gas 

 sand containing fossils, which were thrown out of the well by the 

 explosion of a " shot." The specimens came from well No. 90 of the 

 United Natural Gas Co., which, according to Mr. Harris, is 700' west of 

 and 10' higherthan well No. 91. Mr. Hatch wrote December loth, as 

 follows : " I have sent you some very fine specimens of our gas sand, 

 showing the finest and most perfect fossils that I have seen in this field." 

 Unfortunately, owing to change of residence, these valuable speci- 

 mens have been mislaid among the large collections of Devonian 

 material at Cornell University. At the time of their receipt the fossils 

 were examined rather hastily and Spirifera {^S. disjuncta I think) and 

 RhyncJionella were recognized. 



In March, 1891, Mr. Hatch forwarded me some large specimens 

 of oil sand from another well on the Hatch farm ; but 184' lower than 

 well No. 91. The top of the oil sand in this well is 1236' and the 

 bottom 1270'. The top of the oil sand in this well agrees very closely 

 with that of well No. 91 ; 1415', depth in No. 91, — 184' = 1231', a 

 difference of only five feet. March 27th, Mr. Hatch wrote: 

 " These pieces are different sand from any of those among the samples 

 of well No. 91. The difference between them is that these specimens 

 are from a productive oil bearing rock, while the oil sand of No. 91 

 is a barren rock taking the place of the other and better sand." 



In the interpretation of these well records there are several 

 differences from published observations. 



ist. If the altitude of the mouth of well No. 91 be correct, then 



